Removal of organic nitrogen compounds from hydrocarbons with a zeolite



Feb. 1s, 1960 l REMOVAL OF ORGANICNI'ROGEN COMPOUNDS FROM HYDROCARBONS WITH A ZEOLITE Filed Nov. 26, 1956 R. N. LECK l-:rAL 2,925,381

REMOAL OF ORGANIC NITROGEN COMPOUNDS r FROM HYDRocARBoNs .wrrH-A zEoLlTn Reymond N. Fleck, Whittier, and Carlyle Gj-wiglit,

Fullerton, Calif., assignors to Union Oil Company of California, Los forna f f Angeles, Calif., a corporation of Cali- This -inventionrelates to the refining of hydrocarbons,`

particularly those contaminated with organic nitrogen Because of theseadverse effects; repeated attemptslhave been made to remove, thee'nitrogen compounds from -basic nitrogen lcompounds, i.e., the nitrogen bases or amines. .lt isotherwiser ineffective with respect to the nonbasic nitrogen compounds. Catalytic hydrogenation is effective to remove much of the nitrogen compounds,

required. Treatment of such materials with Fullers earth compounds. Such hydrocarbons include those which are produced as petroleum, as coal tar oil fractions,iand shale oils among others.

Many crude petroleum streams contain considerable quantities of organic nitrogen compounds vin addition to the principal hydrocarbon constituents. the incidence of these nitrogen'compoun'ds is suiiicient that the nitrogen analysisruns as highV as 1.0% by weight. California crude oils in many cases average 0.5% by weight nitrogen. Mexican and Venezuelan crudes have In some cases nitrogen contents ranging from about 0.2%,toV about' 0.35 %v by weight. Extensive analyses of these nitrogencontaining crudes indicate that much of the nitrogen occurs in the formY of amines or the so-called nitrogen bases. These include pyridine, quinoline, and the mono, di, triand tetra alkylated derivatives of these materials. For example, in California kerosene distillate the di, tri, and tetra alkylated quinolines and alkylated pyridines are found. `There is however considerable'nonbasic nitrogen present in these materials. Coal tar oils produced in the coking of coal,fcontain Vextensive quantities of nitrogen bases and these are principally aromatic aminesV and heterocyclic nitrogen compounds. Shale oilrproduced by the heating and retorting of shale rock, such as that which is found in Colorado and elsewhere, re-v sembles waxy crude but is characterized particularly in that it contains such extensive quantities of organicnitrogen compounds that the nitrogen content runs as high as about 2.5% by weight. t Y

A Crude petroleum, coal tar yoils, and shale oils are princitends 'to reducethe quantity of nitrogen compounds, but this involves a, relatively highliquidyield loss through retention of hydrocarbons onthe adsorbent.- The nitrogen compounds are Vlost through disposal 'of the spent Vadsorbent,Y and, seldom if ever is'the nitrogen organic reducedsufliientlytto avoid, the above-mentioned problems in platinum catalyzed reforming.

The presentV invention is'directed to a highly efficient and improved process for'removing the basic organic and non-basic nitrogenqcompounds Vfro-1n petroleum, coal tar, and 4shaleoil crudes, distillates, and other fractions.

Itis a primary object Vof this invention to provide an 'improved-process for the denitrogenation of hydrocarbons contaminated with organicnitrogen compounds. `It is a more specific object ofthis invention to provide a `p'rocessifor the denitrogenation of feed hydrocarbons by. contacting the materialwith alsolid contact material having a specilic vaffinity for organic nitrogen compounds in preference to hydrocarbons of the same boiling range and which .includes a vregeneration step -.in which these nitrogen compoundsy areburned'lfrom the solids by an l oxygen-containing gas.

pal ,or potential sources of liquid fuels. and solvents. The

presence of` nitrogen compounds` in the fuel yor solvent product imparts a very bad odor,` to these materials. Their presence in the original oil very adversely affects hydrocarbon refining techniques by which the fuels'and f i Y t o kthe description 'and illustration thereofiproceed.`

solvents or other materials are produced. They have, for

` example well defined adverse` edects on such processes as catalytic cracking, catalytic isomerization, catalytic revate its active vcracking centers. The cracked gasoline yield may be reduced as much as 50% lthrougllthe pres-V ence of sufiicientV organic nitrogen compounds to give the feed a nitrogen analysis of about 0.3% by weight, and

`It is anotherobjectof this invention to denitrogenate hydrocarbon streams contaminated with Yorganic nitrogen compounds by contacting such streams with a solid metallo :alumino silicate having substantially uniform pores of at least 7 A. in diameter, separating the hydro,- carbonsfrom the Asolids asV a process product, washing the spent vsolids with afsolvent to recover residual quantities of hydrocarbons, regenerating the silicate solids by means of an Yoxygen-containing gas, and recirculating the regeneratedsolids inthe process. Y l It is `a-further object Iof'this invention .to provide a plurality of contact stages inthe process as defined in the foregoing objects. ,v

Bri'ey, the present invention comprises an improved process for treating yhydroc'zarbon streams contaminated with organic nitrogen compounds, and derived from virtually any source ,toiremove such compounds and produce a hydrocarbon stream having a substantially reduced nitrogen analysis..-"In` generalfthe process consists in con-v reduced by when the nitrogen -analysis reaches about 7:*

0.45%. Platinum catalyzed reforming and other reforming processes in'general are also adversely affected by presencel of nitrogen compounds in the feed. InV a platinum catalyzed reforming gasoline reforming system using a halide promoted catalyst, the nitrogen compounds appear to react with the catalyst or the promotor forming ammonium halides which depositY inthe apparatus. This deactivat'es the catalyst andlowers the yield unless Ythe halide is continuously replenished,

1 air oxidationV whereby the adsorbed organic nitrogenY comtacting the hydrocarbon feed mixed with organic nitrogen compounds with a granular'A solidnatural or synthetic metallo alumino silicate zeolite. The organic nitrogen compounds are activelyseparated from the hydrocarbons byfsorption mechanisms and itis possible to produce innitrogen compoundsgis first treated to -separateoccluded Y hydrocarbons. This may be done .by heating withor .withoutstripping,by.solvent-extraction, by light solvent washing, and the like. This Amaterial .is then regenerated by vtlPatentevd Feb. 16,1950

Other objects and .advantages of the present invention j will become more 'apparent to those slrilledin the vart as Contact further 'quantities of the contaminatedieedstock.

` ST-he solid contact material employed in-thevprocess of this `invention is a solid granular materialhaving a mesh size range between about 2 and 300 mesh or smaller, preferably between about 4 and about 30 mesh for static 'or moving solids bed contact, and preferably between 'about 30 and 200 mesh for slurry or fluidized contacts in the liquid or vapor phases, respectively. It may be used in the form of a dense compact bed of material through which the nitrogen compound containingfstreams pass, either in the vapor -phase or inthe liquid phase'. The process may employ a single static bed of material in which case the process'is only sem'ic'ontinuousf "Preferably aplurality of two 'or more staticbeds"'fisolids 'are 'Vemployed iwith'V appropriate @remotelyfoperable"Y Avalving 'so that'the lstreams pass 'through one or more of'fth" con- -ta'ctingl vessels-in av s et"whi1e the' regeneration l*stream passes through one `ormoreof"thefother vessels inthe set. In' this'ease the V'feed "and product fiows 'are continuous, in either the vapor or liquid phase, and either up `'or down through the solids. Y i

l Another moditicationgemploys'a continuously moving solids bed. In this case, the ow of feed is`maintained continuously throughone or more contacting zones. The iiow of regeneration iiuid is maintained continuously through a second contacting zone, and the granular solids are recirculated successively through these Zones.

In another modification using the smaller sized mesh ranges or powdered solids, the ymaterial may be suspended 'or iiuidized in and by the liuid streams contacting it, and a single or several stages are employed. In the liquid phase, a slurry is formed and agitated in each contact zone.

A number of theoretical and actual contact stages greater than one is readily obtained in moving bed systems using a single contacting zone, or with several static beds, or with several slurry or fluidized contacting zones. Plural stage contacting is highly desirable in the production of an efliuent of very low nitrogen analysis, that is, of the order of about 1 ppm. (parts per million) and below. Reduced solids-to-oil ratios also result. A single contact stage is frequently sufficient, even with feedstock of high nitrogen analysis, where the product nitrogen analysis need only be reduced to about 0.1% by weight.

' The present invention may not be carried out with the commonly available solid granular adsorbents such as alumina, silica gel, charcoal, etc. It has been found that the particular materials which are highly efficient and pre-v ferred in the hydrocarbon denitrogenation process of the present invention are thenatural or synthetic crystalline zeolitic metallo alumino silicates activated by partial dehydration and having pores in their crystal structure which are 7 A. or more in diameter. The composition of one typical synthetic zeolite having a pore size of about 13 A. is SNagO-AlgOa- 15SiO2. It may be prepared'by'heating stoichiometric quantities of alumina and silica and excess caustic under pressure. The excess caustic is washed out. Other desired metal ions may then be introduced by ion exchange. Part of the sodium in thismaterial can be ion exchanged with concentrated salt solutions at superatmospheric pressure and temperatures of ISO-300 C. to introduce other'metal ions. These materials are all zeolites and their sodium and calcium derivatives are very stable solids which apparently vhave pores`active for denitrogenation which are quite uniform inV size. Other derivatives havefditerent sizedV pores The metallo alumino silicates havingpore diametersof 7 A. orrnore exert strong denitrogenation'V eiectsvon the organic V nitrogen compounds whereas the hydrocarbons' of the same boiling range are SubstantaIIy-eunalected.

The syntheticcrystalline "metallo aluminoY zeohtes having pore diameters of 7 A. or larger are pressilicate Air Products Company, 30 E. 42nd Street, New York 17, New York, under the name of Molecular Sieves 10X, 13X, etc., and these have pore diameters averaging 10 A. and 13 A. respectively. Y

The process of the present invention will be more readily understood .by Yreference to the accompanying 'drawing which shows` a process `flow diagram of this invention using a series of four Contact stages. It should be understood however that more or fewer .contactstages may in certain instances be required depending upon ythe composition of the feedstock and the desired extent to which thenitrogencontent is to be reduced. The drawing description is conducted in terms of a specific example of the process of this invention Aapplied inthe `denitrogenation of a full range hydrogenated shale oil Coker distillate. The properties of the feedstock are given in Table l. l

TABLE 1 Feedstoek properties Boiling range, F.: Y

Referring now to the drawing, the essential equipment items required in the process are first, second, third, and fourth contactors 10, 12, 14, and 16. These contactors are of the internally battled ymixing vessel type through which a slurry of the oil Vto be treated and the silicate solids are recirculated in suspension. Other major equipment items include spent solids stripper 13 and stripped solids regenerator 20.

The feedstock is introduced at a rate of Y5,000 barrels per day through line 22 controlled by valve 24. lIf desired, a diluent solvent may be introduced through line 26 controlled by valve 2S. Such diluent is not'necessary with the present feedstock, but is Vhighly desirable with heavier' feeds such as coker distillate bottoms and other heavy oils. This feed stream is mixed with the silicate adsorbent flowing through lineV 30 at a rate of 115 tons per day and the mixture passes through line 32 into first contactor'recycle line 34. This material passes through rst 'contactor heater 36 which serves to heat theV feed and maintain the slurry during the contact at about 248 F. The slurry'is recirculated by means of pump 38 at a rate yof 25,000 barrels per day by means of valve 40 up Wardly into and through first contactor 10 from which it overows through line 42, and is recycled.

The first stage effluent is removed from first contactor 10 through line 44 at a rate controlled by valve 46 and is introduced into first etliuentv separator 48; In the drawing this is ,indicated as a centrifuge although conventional settlers and thickeners commonlyused for this purpose may besubstituted. The centrifuge indicated is preferred because of high lthroughput relative to the small physical size of the. equipment. In separator 4S the spent ysolids are separated from the oil, they are washed by'means of normal pentane or other lightl solvent introduced at a rate of 500 barrels per day con-v trolled by -valve 52. Solvent-to-solids 'ratios of between about 1.0 and about 10.0 barrels per `ton may be used; The spent washed solids saturated withV pentane are removed vthrough lineSA-and are :treated ashereinafter described. The solvent vvand "solidsffreeg, oil are removed from separator 48 through'line'56;.and1'pass throughI sols vent vaporizer 58 into separator 60. The solvent 1s rc- Iived ylill'efromas ahvapor. through line 62 andpasses ,i

into 'solvent' recyclev manifold i645; Thel'rst stage efuentoil hows throu-gh'line 66 ata Yrate offabout 4971 barrels per day'and analyzing 0.113 weightpercentniflogen. A m:-

fj'Inthe second by valve 88, and the washed solids are passed' through line at arate o-f 115'tons perday into thetirst'con- |tacto'rg104 in the/.manner described'.v The solventandoil Y stage Aof the-,process eliiuent is com-I bmed with 115 tons per day of silicatel v'adsorbent flowseparator 160. The solventvaporis ntroduced'nto manifoldV 64 by meansofline`162. rTheoil kproduct 'ow's Ythrough'line 164 through cooler"166"and is sent to further processing ,orV storage. facilities, not shown, through line .168 ata rater'r of 4899 barrels'Y perday. .T his oil stream v analyzes The normal pentanesolvent vvaporized from eachf'of the `solventoilmixtures passes vfrom manifold 64 through Vsolvent condenser 170 and is recirculated'as wash liquidr i through liquid solvent manifold 172 to each of the four separators.,Y i Y. 7 f

Invariably a small quantity of the adsorbent is lost in the system throughthe formation of nes and otherwise. Accordinglymakeup metallo valumino silicate is introduced through Vline 174 at a"rate of .about l200 f pounds per day controlled by valve 176. These solids per dayfintroducedthroughline 86v at a ratecontrolled` mixture is removedrfrom second separator'84fthrou'gh line 92,.'is 'passed through solvent vaporizer 94 and introducedinto second vapor liquid separator V96.V The evolved Asolvent vapor ows through line'98 into the recycle solventmanifold 64. The second "stage hydrocarv bon eiuent tows through line 100 and valve 101 at a rate of about 4927 b-arrels per day and analyzes 'nitrogen by weight (Kjeldahl). v

fThe second stage eiuent oil comprises the feed v.to the thirdcontactor 14.Y It is mixed with 115 tons-"perday of silicateadsorbentllowing through linev 102 and thismixfture is introduced into third.contactor recycle line 104 together- ,withfthird contactor overow passing through Y line 106. Themixtureovvs through? third recycle heater A108a1id is recirculatedthrough third contacter 14by vrnear'1-s"ofthird recycle pump 108;t a rateof about 24,' 635barrels per day controlled by valve 110. .Slurry Yfrom the' thirdcontacting zone 14 is passed through line 112 into third separator.. 114. Thespent solids are Y .washed free of occluded oil asbeforeby means of 500 barrels pery 'day' of pentane introduced through line 116 at a'rate controlled byfvalve 118. The washed` solids are removed through line 1720y and constitute the feed solids tothe second contacting zone 12. The solvent and. oilwmixture is removed from third separator 114 .trolled'byvalve 132. This oil'owsat a Vrate of about 4900`barrels per day and has a nitrogen analysis o Y (v).00 ?r ..vveight percent nitrogen (Kjeldahl).

This-oil constitutes the feed to the fourth Vcontacting Y stage andr it ismixed with 115"toi1s per day of lregenerated silicate adsorhentiowing through line ...134. I, This `slurry is introduced into fourthvcontacting yzone recycle line 136 `into admixture with the fourthcontacting `zone is reheatedimfourth contacting Yheater `140V.andnisfrecirculated at a rate of about 24,500 barrels per day vby means of pump 142 controlled byvalve144.Y The oil and'solids ls luri'yxfrom theffourth contacting zouetris re. moved therefrom `through line r146 at a rate controlled by valve 148 andis introduced into fourth-separator 150. The spentV solids are again washed with pentane flowing through line .152 at a rate of about 500 barrels .iper daycontrolledlby valve 154. The washedY solids are passed .byr means of* line 102 and constitute the feed solidsto the third contacting stage. The solvent Yand oil mixture is'. removed from separator 150 through'line 156, y,the pentane is vaporized in heater 158, and the vaporzed 'pentane is Vseparated rtromthevoil in fourth vaporliquid are passedY through lineA 178 intol admixturevwithv regenerateds'ilicate vsolidsjiowi'ngthrough. line 136.

Completelyspent solids areA removed from first separator 48 and ow through linev 54 as previously indicated.

These solidsarefintroduced into ,a ow of inert gas .such as steam iiowing through line V180 at a rate controlled by valve V182.v A suspensionjof solids is thus lformed whichr passescontinuously through line 184 and is introduced upwardly into the bottom ofsolvent vaporizer 18. Hot -regenerated adsorbent at a temperature'ofabout 10509- F. maximum is. introduced into solvent vaporizer 18 vat a rate'of 115 tons per day through line 1786 controlled by valve 188. This serves-to raise the temperature ofthe spent silicate adsorbent to a temperature of about 650 F. The rate ofsteam introduction is controlled relative to the size of the vsolids and the cross Ysectional area of solvent vaporizer. 18 so that a uidized suspension of solids is maintained in .vaporizer'18. With the aid of the steam and the increase in temperature, the pentane solvent is vaporized completely from the solids and thevapor leaves through line '190.r 'This material is condensed in condenser 192 and is -introduced into vapor liquid separator 194. Steam condensate is removed from the bottoni of the separator through line ,196. and the recovered solvent is decanted from the upperA part of separator 196,.and ispassed throughlines 198 and 200 toliquidsolvent manifold 172 by means of pump 202. Stripped solids collect in drawoi line 204, are purged of traces of pentane vapor by `means of steam'introduced` through line,206 at a ratev controlled "by valve 208, and the stripped spent solids are removed from solvent vaporizer 18 through line 210 at a rate of-230 overowgwhich passes through line V'138. A'This mixture .by means of blower 228 throughy line 216 tor line which .air is added as previously indicated.`

Hot regenerated silicate adsorbent 1s drawn F. Thev suspension i'sv passed upwardly into regenerator' y '20 and again the rate is ycontrolled so as to maintain therein auidized suspension .ofthe solids. The organic `nitrogencornpouhds'present inthe solids are burned from the spent `silicatevadsorbent by means` of the air.V

Additional fuel, if needed to maintain the Velevated regenerationtemperature, may be added ,through line 219 at arate controlled by valve 221.* Fluegas ows from the top of regenerator 20 throughlinef 220, and a portionthereof is vented to the atmosphere through line '218 ata rate controlled by'valvef222. The remainder` is ,recirculated in the-regenerator for purposes of temperature control and this material passes through line 224 through recycle gas cooler226 wherein its temperature is reduced to about 750 F. This cooled gas is recirculated y regeneration zone 20 through standpipe 230., A stripping .orV Seal aas, such as' steam, is introduced into theV bottom Y 214 into ou; fumiY lgenerated silicate adsorbent.

18 via line 186.

Through standpipe 234,!into which a seal gas such as steam is introduced'through line 236 for the same purpose as before, are' removed 115 tons per day of rc- These materials are passed through line 238 into combination with fresh solids introduced through line 178.: The mixture of solids is recirculated in the process through line 136 asdescribe'd.

In the foregoing example the metallo 'alumino silicate adsorbent had aucomposition corresponding to and had substantially uniform vpores .of about 13 A. in

of at .least17 A. `forit' hasbeendetermine'd 'that .substantially no Yeffective ,denitrogenation resultsl with these metallo alumino silicatesrwhen'thepores are '4 or 5 A. in

diameter.

In the foregoing process, `four contact stages were employed. This number is seen to be suicient to reduce the nitrogen analysis from 0.160 weight percent to 0.0005% or p.p.m. In those situations vwhere itis not necessary that .the product oil have such Va'low nitrogen analysis or in which the feedstock does not have such a high nitrogen analysis, then fewer than four contact stages ,may be employed. It is obvious from the previous description the manner in which more or fewer than four contact stages would be employed. In the event that a single contact stage is suicient, the oil feed indicated as in the drawing as being introduced through line 22, may be introduced instead into the single contacting zone at point F indicated in the drawing at line 138. Spent washed silicate adsorbent is removed from separator 150 vat point R at line 102 and introduced into the solvent vaporizer 18 in the same manner. generated solids are introduced into the system at the same points shown. In this single stage modification, the first, second, and third contacting zones, .and the associated elements are not necessary and may be elimi nated.

The process of this invention is readily applicable in the denitrogenation of very heavy oil feeds contaminated with organic nitrogen compounds. -In the preliminary distillation of cracking stock fed .to a uid catalytic cracking unit, approximately 9.5% by volume of a heavy bottoms material is produced. This material has an initial boiling point of 715 F., the end point being unknown since cracking begins at about 850 F. The API gravity is 33. The nitrogen analysis (Kjeldahl) is 0.198%. ume of toluene. This 50-50 mixture was Vcontacted in a single contacting stage with 105 pounds of l0 A. metallo alumino silicate solids per barrel of oil-solvent mixture. The contacting temperature was maintained at about 248 F. The product oil after separationof the solvent analyzed 0.068% by weight nitrogen (Kjeldahl). This constitutes a v66%.removal of the organic nitrogen compounds ina single contacting stage. In those cases where lower nitrogen analysis is desirable in the subsequent use of the. feedstock, additional contacting stages are readily utilized to the point that substantially complete removal of nitrogen compounds is effected if necessary. p

In the foregoing example in which toluene was used as a diluent, and in the description of the drawing in which pentane was used to wash` spent solids and as a diluent if required, in each case the solvent employed was a relatively low boiling hydrocarbon solvent. Preferably, the solvent shouldV have aboiling point or range which is substantially below the initial boiling point of Recycled re- -f This material was diluted with an equal volf the hydrocarbon "being ltreated forr denitrogr'en'ation.

Aromatic, parafdnic, naphth'enic, or olenic hydrocarbon solvents may be'employed. Hydrocarbon solvents -are preferred since they' are' highly' compatible with lvirtually every ,hydrocarbon feedstock treated according tothe present invention. yIn'some'cases other organic solventsY may be substitutedsuch as the alcohols, liquid aldehydes,

'ketones,' and the like.

.The process of the present invention is particularly applicable to the "denitrogenation of the hydrocarbons in the gasoline boiling range. The removal of organic nitrogen compoundsV in such instances is extremely important for several reasons. First, such compounds impart tov gasoline' an extremely disagreeable odor. Second, the presence of even very lsmall concentrations 'of such nitrogen compounds has an extremely adverseeie'ct upon the performance of 'certain halide-promoted 'platinum catalyzed "dehydroaromatiza'tion 'processes employed in thereiining of gasoline to raise the antiknock'r'ating thereof. The nitrogen compounds'appear to react either with the h'alide'promoter or the catalyst in some manner with the formation of extensive quantities of ammonium halide salts which precipitate in the system and cause plugging problems. Third, and in addition to the plugging problems, the ammonium halide formation, if 'allowed to continue, also simultaneously tends to deactivate the catalyst through removal of theY promoter and ultimately results in decreased yields and octane provement. Y

A gasoline feedstock intended for catalytic dehydroaromatization had a nitrogen analysis of 9L7 p.p.m. This material was treated in the process 'according to the present invention to reduce the nitrogen content to levels suiiicient to avoid detrimental` effects in the subsequent treatment. The feedstock was'contacted in the vapor phase in a single contacting stage with the 13 A. metallo alumino silicate at a'liquid hourly space 'velocity of 14 volumes per volume per hour. The temperature was 425 F. The product oil analyzed 0.5 p.p.m. of nitrogen.

it has been found that in the embodiment of the process of this invention in which the denitrogenation is conducted in the liquid phase, contacting temperatures on the order of F. are adequate `to effect a substantial degree of denitrogenation. It has been found also that at higher temperatures the rate of denitrogenation is considerably higher as indicated by the lower nitrogen analyses of the products, Yparticularly in the liquid phase with fairly heavy feedstocks. 'Preferred contacting temperatures are from about 80 F. to 'about 500 F. It should be understood that the process of the present invention may likewise be applied with tine or powdered solids in the vapor phase, `exactly as was done in the vaporization of solventand in the regeneration of spent solids in the description of the drawing. A certain amount of multi-stage contacting may be obtained in this manner, although it is more readily ob tained using a pluraltiy of uidized contacts.

The solids-luid contact may also be conducted using a static bed of the metallo alumino silicate, and if desired a moving solids bed may be employed with countercurrent fluid ilow so that a greater plurality of contact stages may be obtained. These contacts may also be eifected in either the vapor or liquid phase. With lighter feedstocks it is preferred to treat them inthe vapor phase because the holdup on the solids of feed hydrocarbon is considerably reduced and the denitrogenation rate is higher. With heavier feedstocks it is possible to treat them in the vapor phase by contacting them at reduced pressures with the silicate adsorbent. Itis also possible to so treat them by employing diluent gases such as hydrogen, nitrogen, carbon monoxide, carbon dioxide, methane, and other well known light and inert gases. With the very heavy feedstocks the contact must of necessitybe conducted' i'n the liquid 'phase thse materials-fare; frequently nonvaporizable. Y Iheir contact'- ing is facilitated underV these vcircumstances with the use of diluentfsolvents.. 1:.-..1::f= i Y Y t Y in the''hydrocarbonmixtu remitir` each contacting zone, and

. A particularenibodimentof hepresentinventionfhas been hereinabove described-.2inT considerablekdetail `by way of illustration. 'It should bewunderstood thatvarious other-modifications; and-adaptations. thereof VmayV be made by those skilled'in this particular art ,without departing from the spirit andsco'pe of this invention as set forth inthe appendedclaims.

We claim: .f i `l. A' process forthe denitrogenation oa-a normally liquidhydrocarbon mixture` derived from :a material selected from the class consisting of petroleum, shale oil and coal taroil, said mixture being contaminated with normally vincident organicnitrogen-compounds of substantially the same boilingJange, Iwhich process comprises contacting said mixtui'efpwith asolid partially ded hydrated-'zeolitic metalloalumino silicate-adsorbent hav- Y ing substantially uniform poresl at least 7jA. indiameter, therebysorbing said-organicnitrogencompound rafting1 ,af hydrocarbon mixture? ofY reduced nitrogerr 'content from the adsorbent; and-contacting the adsorbent containing sorbedV nitrogencompoundswith an oxygencontaining gas while controlling the temperature atvalu'es below 'aboutillOO' F."suicient totrburn saidxsorbed nitrogen -compounds; therefrom'- 'and' regenerate'A said ad-r sorbnt.

2. A process according .to claim"llwhereinthefsaid contacting step is carried out ata temperature between about 80 F. and about'SOO". F.

"3. A process according to claim 1 in combination withY spent-adsorben infrsaidvaporizorfzone niaintaininga'V the steps of diluting said hydrocarbon mixture with a light hydrocarbon solvent boiling below the initial boil ing point of said mixture,fand'separatingthe said solventfrom said hydrocarbon eluent.

4; A process according toclaim l-wherein said metallo alumino silicate has a composition Acorresponding substantially to 5Na206A13O315Si03 and has pores of about 13 A. in diameter,

5. Aprocess according to claim 1 wherein said hydrocarbon'mixture is a petroleum hydrocarbon distillate.

6. A process according to claim 1 wherein said hydrocarbon mixture is derived from shale oil.

7. A process for the denitrogenation of a normally liquid hydrocarbon mixture derived from a material -selected from the class consisting ofV petroleum, shale oil, and coal tar.oil, rsaid mixture being contaminated with normally incidentorganic nitrogen compounds of Ysubstantially the same boiling range, which process comprises establishing a plurality of serially connected con: tacting zones; maintaining within each of said contacting zones a bed of a solid partially dehydrated zeolitic metallo alumino silicate adsorbent having substantially uniform pores at least 7 A. in diameter; passing said hydrocarbon mixture into the first of said contacting zones and thence through the remaining of said contacting zones in series, whereby said mixture is broughtinto intimate contact with the adsorbent contained in each of saidfzones and the said 'nitrogen compounds are sorbed on'said adsorbent; passing said adsorbent through said contacting zones in series counter-current to the flow of said hydrogenerate the same; and recirculating said regenerated heatngthe iet-.circulating stream tomaintain a contacting temperature between 'about 8091,". and'about 500"v P. v19g. A process according toclaim v8 in combination with the step Vofremoving a slurry strearnjfrom each contactinggzone, introducingit in to a communicating. solids-duid separator zone,'and separating the solidadsorbent from lsaid hydrocarbontherein. f.;V v i 10. A proces'sfaccordingfto claim 9.in combination with the step :of applying-centrifugal forcesto said solid adsorbent during separation of the same from said hydro-. carbon... Y r` jt 1l. A p rocessiaccordingto'claim 9 in combination withzthegstepsfoiiwashing 'said solid adsorbent with along boiling solventto remove occluded hydrocarbon ,therefrom, heating the.effluentA from each of said separator zones to vaporizegsaiodflow boiling solvent,n and V,separatel ingthe solvent Yvapor from said hydrofcaijbon..

12. A process according to claim 11 in combination withfthe lst eps of passing the solvent-washed spent ad,

regenerationfgas.; iv Y Y .13; A Plocess,'accordingtoclaim12 in combination Wlth ythe Stepsnf maintaining .a .uidizedbodyiof :said

uidized bod 0. .said silicate; Solids -in la; i. .regeneration zone durinacontactzuitli t11.eoiyse.n.coiitainiilssas,and.4

recirculating a suicient amount of hotv regenerated adsorbent Afrom said regeneration zone Vto saidvaporizer zone to heat said spent adsorbent and vaporizesaid S01- YJvent therefrom.

14. A process according to claim 13 wherein said adsorbent in said vaporizer zone is maintained in the fluidized state by controlling the upward velocity of steam therethrough.

15. A process according tol claim 7 Ywherein said metallo alumino silicate has a composition corresponding substantially to 5Na2O-6A13O315Si02 and has substantially uniform pores of about 13 A. in diameter.

A process for the denitrogenation of a normally liquid hydrocarbon mixture derived from a material selected from the class consisting of petroleum, shale oil,

and coal tar oil, said mixture being contaminated with normally incident lorganic nitrogen compounds of substantially the'same boiling range, which process comprises passing said hydrocarbon mixture through a plurality of solid-huid contacting zones, contactingr Said mix- Ature therein with a partially dehydrated zeolitic solid metallo alumino silicate adsorbent having substantially uniform pores of at least 7 A. in diameter to sorb the said organic nitrogen eompounds and produce a hydro with the steps of circulating a liquid slurry of said hyadsorbent to the last of said contacting zones tocom-v u plete the circulation of adsorbent.

8. A. process according to claim 7 in combination with the stops of circulating a liquid slurry of said adsorbent carbon product of substantially reduced nitrogen content, and .spent adsorbent, removing occluded hydrocarbon from said spent adsorbent, regenerating said adsorbent by contact with an oxygen-containing gas to burn said organic nitrogen compounds therefrom, and contacting additional hydrocarbon mixture with the regenerated ad-V sorbent.

.17, A process according to claim 16 wherein said mixture contacts said metallo alumino silicate in the Yvapor phase.` Y i 18. A process accordingto claim 16 wherein said mix- Y turecontacts said metallo alumino silicate in theliquid phase.

V1,9. A process according to claim 16 in combination 'drocarbon mixture and said `metallo alumino silicate adsorbentthrough each of the contacting zones, owing a slurry stream from each contacting zone into a centrif-v ugal separator zone, contacting said adsorbent separated e therein with a low boiling hydrocarbon solvent obtain.

extracted adsorbent and a solvent-hydrocarbon mixture,

separating and recycling the solvent leaving a hydrocaresegesi extracted adsorbentA from: allV bntlthe irst ,separator` zone-` into the; previousl contacting zone,v introducing the hydrocarbon eiuent from 'all but theA last separator zone into the subsequent't contacting zone",` producing the hydrocarbon effluent from thelastA separaten'V z'oner assaid hydrocarbon product` ofsubstantially reduced nitrogen content, introducing the extracted adsorbent ffromthe rsthseparator vzone into a solvent vapor-iler zone, heating' and stripping saidv extracted adsorbent therein to separate residual' solventV from the adsorbent, recycling the recovered solvent, introducing the stripped adsorbent into aregeneration zonewhereinv the adsorbent is contacted with said oxygen-containing gas, controlling the temperatures therein below about- 1`1001 F. to burn sorbed organic nitrogen compounds therefrom forming regenerated solids; said regenerated adsorbentV being introduced into the lastl contactingl zone completing the adsorbent cycle. f

' 20. The process'- for deni-trog'enating a normally liquid hydrocarbon feed mixture derivedl from a material selected from't-he class consisting of petroleum, shale oil, and coal tar oil, said feed mixture beingcontaminated with normally incident organic nitrogen compounds of substantially the same boiling range, which'process comprises introducing said feed mixture into a contacting zone and therein contacting it with a solid partially dehydratedI zeolitic metallo alumina silicate molecular'- sieve V adsorbent. having substantially uniform pores at least v7 Af =in diameter, tivherebyi-v saidA organici, nitrogen; contr;

pounds are'Y s'orbed'; andi withdrawing from. said contacting; zone a hydrocarbon product mixture having an organic nitrogen compound content substantiallyy lower thanl that of'said hydrocarbon feed mixture.

21. A process'4 as dened by' claim 20 wherein said-feed mixture is contacted with said adsorbentuwhile in the vapor phase.

22. A process asy dened by claim 20' wherein said; feed mixture is contacted. with said adsorbent while in the liquid phase.

23. A process as defined by claim 20 ,wherein sa'id hydrocarbon feed mixture is a petroleum: hydrocarbon mixture of thegasolinevboiling range.

Selective Adsorption with; Zeolites,Chemical;& EngLv neering News vol. 32, Nov.v 29, 195,4, page 4786.

Union Carbides Physical Properties of Linde li/[olccular- Sieves, Form 9947fA, Aug. 1,79, 19,571. 

1. A PROCESS FOR THE DENITORGRENATION OF A NORMALLY LIQUID HYDROCARBON MIXTURE DERIVED FROM A MATERIAL SELECTED FROM THE CLASS CONSISTING OF PETROLEUM, SHALE OIL AND COAL TAR OIL, SAID MIXTURE BEING CONTAMINATED WITH NORMALLY INCIDENT ORGANIC NITROGEN COMPOUNDS OF SUBSTANTIALLY THE SAME BOILING RANGE, WHICH PROCESS COM PRISES CONTACTING SAID MIXTURE WITH A SOLID PARTIALLY DEHYDRATED ZEOLITIC METALLO ALUMINO SILICATE ADSORBENT HAVING SUBSTANTIALLY UNIFORM PORES AT LEAST 7 A. IN DIAMETER, THEREBY SORBING SAID ORGANIC NITROGEN COMPOUNDS, SEPARATING A HYDROCARBON MIXTURE OF REDUCED NITROGEN CONTENT FROM THE ADSORBENT, AND CONTACTING THE ADSORBENT CONTAINING SORBED NITROGEN COMPOUNDS WITH AN OXYGENCONTAINING GAS WHILE CONTROLLING THE TEMPERATURE AT VALUES BELOW ABOUT 1100*F. SUFFICIENT TO BURN SAID SORBED NITROGEN COMPOUNDS THEREFROM AND REGENERATE SAID ADSORBENT. 